class_docstr: Base class for training runner implementations.
docstr: Returns the runners training instance.
  :return: Instantiated trainer.
docstr_tok: ["Returns","the","runners","training","instance",".",":","return",":","Instantiated","trainer","."]
code: def trainer(self) -> Trainer:
      """Returns the runners training instance.
      :return: Instantiated trainer.
      """
      return self._trainer
  
imports: import logging
  import os
  import dataclasses
  from typing import Optional, Callable, Union
  import omegaconf
  from omegaconf import DictConfig
  from maze.core.env.structured_env import StructuredEnv
  from maze.core.env.structured_env_spaces_mixin import StructuredEnvSpacesMixin
  from maze.core.utils.config_utils import EnvFactory, SwitchWorkingDirectoryToInput
  from maze.core.utils.factory import Factory
  from maze.core.wrappers.observation_normalization.normalization_strategies.base import StructuredStatisticsType
  from maze.core.utils.seeding import set_seeds_globally, MazeSeeding
  from maze.core.wrappers.observation_normalization.observation_normalization_utils import obtain_normalization_statistics, make_normalized_env_factory
  from maze.core.wrappers.observation_normalization.observation_normalization_wrapper import ObservationNormalizationWrapper
  from maze.core.wrappers.wrapper_factory import WrapperFactory
  from maze.perception.models.model_composer import BaseModelComposer
  from maze.perception.models.space_config import SpacesConfig
  from maze.runner import Runner
  from maze.train.trainers.common.model_selection.best_model_selection import BestModelSelection
  from maze.train.trainers.common.trainer import Trainer
  from maze.utils.bcolors import BColors
  from maze.utils.log_stats_utils import setup_logging
label_desc: Use image node_id 6 for calling the TrainingRunner obj's underlying member method code with example usage: obj.trainer() and returns: self